Those are the Outsak UL bags. The one on the left is the larger size, and I had David make me a custom size (the one on the right) that is half-way between the large and the small in height. The custom one is my favorite, volume-wise, for 3 nights out.
The weights of each Outsak UL, with cuben liner, mylar, 40' of Lawson's Ironwire cord, a couple of mini-'biners, and my long titanium spoon are as follows (with dimensions):
Large, 18" x 10" = 6.5 oz.
Medium, 16" x 10" = 6.0 oz. (my custom size)
Small. 14" x 10" = 5.4 oz.
Aside from bears and Valerie's post-doc ravens, I would bet on these bags thwarting any of the usual suspects out there. In Glacier and Yellowstone, I just toss the hang cord over the bear pole and tie it off. In Colorado, where I only have to worry about Greg, Mags, Skurka, Stuart, Brendan, the Randys, and Gordon trying to sneak my whisky, I just hang it from a tree branch maybe 5' up. It's cheap entertainment, watching a chipmunk clinging to the mesh trying in vain to chew a hole in it. In the unlikely event that some pest could breach the SS mesh, it would be hard for it to chew through the 1.0 oz./yard cuben bag. And I like the fact that the cuben bag, when rolled over at the top, is a waterproof food container when it rains.